Bootstrap Loader - Process of locating the operating
system. If capable Operating system located BIOS will pass the control
to it

BIOS - Software / Drivers which interfaces between the
operating system and your hardware when running DOS or Windows you are
using complete BIOS support

CMOS Setup - Configuration program. Which allows you
to configure hardware settings including system settings such as computer
passwords, time, and date?
Computer hardware are divided into 3 parts

BIOS manufacturers: American Megatrends, Phoenix, and
Award

CMOS - Stores around 64K of Programming Short for complementary metal oxide
semiconductor. Pronounced see-moss, CMOS is a widely used type of semiconductor.
CMOS semiconductors use both NMOS (negative polarity) and PMOS (positive
polarity) circuits. Since only one of the circuit types is on at any given
time, CMOS chips require less power than chips using just one type of
transistor. This makes them particularly attractive for use in battery-powered
devices, such as portable computers. Personal computers also contain a
small amount of battery-powered CMOS memory to hold the date, time, and
system setup parameters.

How to enter a typical CMOS setup: When PC boots up you will be told to
press a key to get to setup:

Note: some new motherboard
designs allow access to the CMOS setup to be disabled through a motherboard
jumper. If you cannot access the setup using the proper key commands stated
above check your motherboard settings to see if the access has been disabled.